1. The Field of the Invention
The present invention relates to backing up and restoring computer data. More specifically, the present invention relates to systems and methods for minimizing the loss of computer data when restoring computer data that was lost due to the interruption.
2. The Prior State of the Art
With the advent of personal computers, businesses worldwide rely on computer data in performing daily business routines. However, a variety of events such as natural disasters, terrorism, or more mundane events such as computer hardware and/or software failures can occur while a computer is processing. These failures often result in causing the computer data to become corrupt, unreliable, or even lost. The corruption or loss of data, such as customer lists, financial transactions, business documents, business transactions, and so forth, can cause havoc to businesses by resulting in the loss of large investments of time and/or money.
The loss or corruption of computer data is particularly devastating in the world of electronic commerce. The Internet has allowed individuals all over the world to conduct business electronically, thereby resulting in the continual upload of electronic orders. However, all copies of the orders are electronic and thus corruption or loss of the electronic computer data can result in the loss of the business represented by the lost orders.
Recognizing the commercial value of reliable computer data, businesses seek ways to protect their data and to reconstruct data that has become corrupt, unreliable, or lost. Traditional approaches of data protection and reconstruction have involved creating a backup copy of the computer data. While it is a simple procedure to preserve a backup copy of an individual file on a floppy disk, the creation of a backup copy becomes more difficult as the amount of data increases.
Perhaps one of the simplest approaches to creating a backup copy of a large volume of computer data is to copy the data from a mass storage system to an archival device, such as one or more magnetic tapes. This method stores large amounts of computer data at the expense of immediate access to the data. The magnetic tapes are stored either locally or remotely, and the data is copied from the magnetic tapes to the mass storage system when problems arise with the mass storage system.
While the use of an archival device to preserve data loss has the advantage of being relatively simple and inexpensive, it also has severe limitations. One such limitation is the amount of time that prevents user accessibility to the computer data while a backup copy is created and while data is reconstructed. The prevention of user accessibility has traditionally been required to ensure that no data has changed during the process. Because user inaccessibility of data is undesirable, backup copies are created less frequently, thereby causing the computer data in the backup copy to become stale. Similarly, transferring computer data from a magnetic tape to a mass storage system can become very lengthy because the computer data is transferred on a file-by-file basis. The time is further lengthened when the archival mass storage device is remotely located and is not accessible over a network. These long reconstruction periods result in extended computer inaccessibility and cost businesses increased amounts of time and money.
Another limitation of the traditional methods is that the backup copy represents data as it existed at a previous instant in time, meaning that the backup copy is not current with subsequent changes made to the original copy. The creation of a backup copy provides the security that a large portion of the computer data can be recovered in the event that the original copy becomes corrupt or lost. This limits the loss to include only the changes made to the original copy since the creation of the last backup copy. However, in some businesses, if the computer data is not current, the data is stale, unreliable, and even useless. This is particularly troubling in the financial world where rates and information change with great frequency. Thus, when the computer data becomes corrupt or lost, the businesses that rely on information that changes frequently are exposed to the risk of losing all of their valuable computer data.
It would, therefore, represent an advancement in the art to have a system and method for backing up computer data that could further minimize the amount of computer data that is lost due to a computer failure or corruption of data. It would also represent an advancement in the art to have a system that allowed data to be backed up without terminating user access to the mass storage system.